Wide-area measurement systems (WAMS) have made possible the monitoring of overall bulk power systems as well as provided insights into system dynamics. Phasor measurement units (PMU) have been deployed in many points of a power grid system to measure phasor parameters, such as frequency, amplitude and angle of the electrical supply in a 3-phased alternating current (AC) electric power grid. A type of single-phase Phasor Measurement Unit (PMU) known as a Frequency Disturbance Recorder (FDR) may be used for amplitude, angle, and frequency measurements at a typical distribution level electric outlet. Typical PMUs and FDRs require direct electrical contacts with the power lines to sense the electric signals, making the setup process for the PMUs and the FDRs relatively complex and costly. PMUs may employ current transformers physically connected to the transmission line, transformers or bus to obtain current signals/information, and potential transformers physically connected to the transmission line, transformers to obtain voltage information for synchrophasor measurement. However, the physically connection of PMUs results in high installation and maintenance costs. The high installation and maintenance costs limited installation and widespread use of PMUs. In addition, PMUs may be deployed in substations to monitor electric power systems, so they have low accessibility and portability. In remote areas, it may be difficult and inconvenient to set up a PMU or FDR, which may be typically bulky and expensive. The low accessibility and low portability limits the deployment locations of PMUs in wide-area electric systems.
Therefore, there may be a need for a portable inexpensive type of PMU/FDR systems that can function in remote locations without significant performance degradation or complex setup processes.